Wellbores are drilled to locate and produce heavy oil and other forms of hydrocarbons. During drilling, an operator may take actions to evaluate and/or measure properties of subterranean formations that may be encountered, including the liquids and/or gases existent in the subterranean formations. In some cases, the drillstring utilized to create the wellbore is removed, and a wireline tool is deployed within the wellbore to test, evaluate, and/or sample the liquids and/or gases in the subterranean formations. In other cases, the drillstring itself may be provided with devices operable to perform such testing, evaluation, and/or sampling without having to remove the drillstring from the wellbore.
An example of such downhole tools is operable to obtain dielectric measurements of the subterranean formation by emitting electromagnetic energy into the subterranean formation and detecting changes in the energy as it exits the formation. However, utilizing such tools in the evaluation of heavy oil sands may be complicated by low salinity formation water, which reduces the observed contrast between the resistivity of the water and the oil sands.